Neonates Flashcards
what cells produce surfactant?
type 2 pneumocytes
when are type 2 pneumocytes mature enough to produce surfactant?
between 24-34 weeks gestation
what is surface tension?
attraction of the molecules in a liquid to each other, pulling them together and minimising surface area
what does surfactant do?
reduces surface tension - maximising the surface area of the alveoli and increase compliance
what does the squeezing of the thorax at birth do to the lungs?
helps clear fluid from the lungs
what stimulates the first breath of a baby and why is it important?
Birth, temperature change, sound and physical touch stimulate the baby to promote first breath
Strong first breath= required to expand previously collapsed alveoli for the first time. Adrenalin and cortisol are released in response to the stress of labour, stimulatory respiratory effort.
how does the first breath lead to the closure of the foramen ovale?
first breath = expands alveoli = decreased pulmonary vascular resistance = fall in pressure in RA, = LA pressure higher = functional closure of foramen ovale
what causes the closure of the ductus arteriosus?
Prostaglandins keep ductus arteriosus open, increased blood oxygenation causes a drop in circulating prostaglandin
what causes the ductus venosus to close?
Immediately after the ductus venosus stops functioning because the umbilical cord is clamped and there is no blood flow in the umbilical veins. The ductus venosus structurally closes a few days later to become ligamentum venosum.
what constitutes very low birth weight and extremely low birth weight?
Very low birth weight = <1.5kg
Extremely low birth weight = <1kg
describe the affects of hypoxia in normal labour?
Normal labour and birth leads to hypoxia. contractions = placenta is unable to carry out normal gaseous exchange = hypoxia.
Extended hypoxia = anaerobic respiration and bradycardia. Further= reduced consciousness and a drop in respiratory effort, in turn worsening hypoxia.
Extended hypoxia= Hypoxic-ischaemic encephalopathy (HIE), with potentially life changing consequences such as cerebral palsy.
4 issues in neonatal resuscitation
- hypoxia
- large surface area to weight ratio = get cold easily
- wet = lose heat rapidly
- babies born through meconium may have this in mouth/airway
what are the principals of neonatal resuscitation?
-
warm the baby
- get dry asap, heat lamp, <28 weeks in plastic bag under lamp
- apgar
-
stimulate breathing
- vigorously dry with towel
- head in neutral position, check for obstruction
-
inflation breaths
- given when gasping or not breathing despite adequate stimulation
- compressions
when is APGAR calculated
1, 5, 10 mins after birth
what is the APGAR score?
how are inflation breaths given?
- Two cycles of five inhalation breaths (lasting 3 seconds each) can be given to stimulate breathing and heart rate
- If there is no response and HR low, 3 seconds ventilation breaths can be used
- If there is still no response, chest compressions can be used, coordinated with the ventilation breaths.
Technique very important.
Air for term or near term babies
mix of air and oxygen in pre-term babies.
O2 sats can be monitored throughout if there are concerns about breathing.
Aim for gradual rise and do not exceed 95%
what is delayed cord clamping?
allows for more blood to enter the circulation of the baby.
AKA PLACENTAL TRANSFUSION.
Recent evidence indicated that in healthy babies, delaying Hb= Hb, Iron stores and BP and a reduction in intraventricular haemorrhage and necrotising enterocolitis.
The only apparent negative affect is neonatal jaundice, potentially requiring phototherapy.
what is the current guideline on delayed cord clamping?
uncompromised neonates - delay of at least 1 minute following birth
neonates requiring resus - clamped sooner to prevent delays in getting resus
what needs to happen to the baby immediately after birth?
- Skin to skin
- Clamp the cord
- Dry the baby
- Keep the baby warm in hat and blankets
- VitK
- Label the baby
- Measure the weight and length
why are babies given vitamin K shortly after birht?
Babies are born with a deficiency of VitK. IM injection in the thigh shortly after birth. Can have a helpful side effect of stimulating the baby to cry, which helps expand the lungs. Vitamin K helps prevent bleeding, particularly intracranial, umbilical stump, and GI bleeding. Alternatively, vitamin K can be given orally, however this takes longer to act and requires doses at birth. 7 days and 6 weeks.
what is the benefit of skin to skin contact?
- Helps warm baby
- Improves mother and baby interaction
- Calms baby
- Improves breastfeeding
when is breast/bottle feeding initiated?
as soon as baby is alert enough
when does the newborn examination need to be conducted by?
within 72 hours
when is the newborn hearing test conducted and what is it?
first 4 to 5 weeks
automated otoacoustic emission (AOAE)
what is the blood spot screening test, what does it test for and when is it done??
9 genetic conditions.
Is taken on day 5 (day 8 at the latest) after consent from the parent.
A heel prick is used to provide drops of blood. Screening card requires four separate drops.
- Sickle cell disease
- CF
- Congenital hypothyroidism
- Phenylketonuria
- Medium-chain acyl-CoA dehydrogenase deficiency (MCADD)
- Maple syrup urine disease
- Isovaleric acidaemia (IVA)
- Glutaric aciduria type 1 (GA1)
results come back in 6-8 weeks
what is a caput succedaneum?
oedema collecting on the scalp - outside the periosteum
caused by pressure to a specific area of the scalp during traumatic, prolonged or instrumental delivery
crosses the suture lines
resolves spontaneously in a few days
what is a cephalohematoma?
collection of blood between the skull and periosteum
caused by damaged blood vessels during traumatic, prolonged or instrumental delivery
DOES NOT cross suture line
causes discolouration of skin in selected areas
normally resolves in a few months with no intervention
risk of anaemia and jaundice due to blood collecting within haematoma & breakdown
monitor for anaemia, jaundice and resolution
what is facial paralysis?
facial nerve palsy from forceps delivery
normally resolve spontaneously
may require neurosurg input if doesn’t resolve
what is Erb’s Palsy?
injury to C5/C6 nerves in brachial plexus during birth
associated with shoulder dystocia, traumatic or instrumental delivery and large birth weight
how does erbs palsy present
damage to C5/C6 nerve leads to weakness of shoulder adbuction and external rotation, arm flexion, finger extension
- waiters tip:
- Internally rotated shoulder
- Extended elbow
- Flexed wrist facing backward
- Lack of movement in the affected arm
what is the prognosis for erbs palsy
usually resolves spontaneously within a few months
may require neuro surg input
what is a fractured clavicle associated with?
shoulder dystocia, traumatic/instrumental delivery, large birth weight
how does a fractures clavicle present?
- Noticeable lack of movement or asymmetry of movement in affected arm
- Asymmetry of the shoulders, with affected shoulder lower than the normal shoulder
- Pain and distress on movement of the arm
how is a fractured clavicle conformed and managed?
Confirmed w/ USS or XR.
Management conservative, occasionally with immobilisation of the affected arm. It usually heals well.
Main complication of a clavicle is injury to the branchial plexus, with subsequent nerve palsy.
what is neonatal sepsis?
caused by infection in the neonatal period - potentially fatal
presents with very non specific signs
low threshold for starting broad spec abx
what are some common organisms in neonatal sepsis?
group B streptococcus
Escherichia coli
Listeria, Klebsiella
Staphylococcus aureus
what are some clinical features of neonatal sepsis?
- Fever
- Reduced tone and activity
- Poor feeding
- Respiratory distress or apnoea
- Vomiting
- Tachycardia or bradycardia
- Hypoxia
- Jaundice within 24H
- Seizures
- Hypoglycaemia
what are some red flags for neonatal sepsis?
- Confirmed or suspected sepsis in mother
- Signs of shock
- Seizures
- Term baby mechanical ventilation
- Respiratory distress starting more than 4H after birth
- Presumed sepsis in another baby in multiple pregnancy
how is neonatal sepsis treated?
local guidelines
- Risk or clinical feature, monitor observations and clinical condition for at least 12H
- 2+ risk factors or clinical features= start ABX
- ABX start if single red flag
- ABX should be given within 1H of making decision to start them
- Blood cultures should be taken before abx given
- Check baseline CRP and FBC
- Perform LP if infection strongly suspected or there are features of meningitis
what antibiotics are given in neonatal sepsis?
benzylpenicillin and gentamycin
3rd gen cephalosporin given in lower risk babies
what ongoing management is required for neonatal sepsis?
Check CRP again at 24H and check the blood culture at 36H
Consider stopping abx if clinically well, the blood cultures are negative at 36H after taking them and both CRP<10
Check CRP at 5 days if still on treatment
Consider stopping abx if clinically well, LP and Blood cultures negative and CRP normal at 5 days.
Consider LP if any CRP>10
Urgent refer temp= <3/12 temp >38, 3-6/12 >39 or >5/7
what is hypoxic-ischaemic encephalopathy?
occurs in neonates as a result of hypoxia during birth.
Hypoxia is a lack of oxygen
ischaemia refers to a restriction in blood flow to the brain
encephalopathy refers to malfunctioning of the brain.
is hypoxia normal in childbirth?
Some hypoxia is normal during birth, however prolonged or severe hypoxia leads to ischaemic brain damage
HIE can lead to permanent damage to the brain, causing cerebral palsy. Severe can result in death.
when should HIE be suspected?
Suspected HIE in neonates when there are events that could lead to hypoxia during the perinatal or intrapartum period, acidosis (pH < 7) on the umbilical artery blood gas, poor Apgar scores, features of mild, moderate or severe HIE (see below) or evidence of multi organ failure.
anything that lead to asphyxia can cause HIE, what are some examples?
- Maternal shock
- Intrapartum haemorrhage
- Prolapsed cord, causing compression of the cord during birth
- Nuchal cord, where the cord is wrapped around the neck of the baby
what is the Hypoxic-Ischaemic Encephalopathy Grades (Sarnat Staging)?
how is HIE managed?
neonatal unit - supportive care with neonatal resuscitation and ongoing optimal ventilation, circulatory support, nutrition, acid base balance and treatment of seizures.
Therapeutic hypothermia - in some cases - to help protect the brain from hypoxic injury.
Children will need to be followed up by a paediatrician and the multidisciplinary team to assess their development and support any lasting disability.
what is Therapeutic Hypothermia?
Babies near or at term considered to have HIE can benefit from therapeutic hypothermia.
Involves actively cooling the core temperature of the baby according to a strict protocol.
transferred to neonatal ICU and actively cooled using cooling blankets and a cooling hat.
The temperature is carefully monitored with a target of between 33 and 34°C, measured using a rectal probe.
This is continued for 72 hours, after which the baby is gradually warmed to a normal temperature over 6 hours.
The intention of therapeutic hypothermia is to reduce the inflammation and neurone loss after the acute hypoxic injury.
reduces the risk of cerebral palsy, developmental delay, learning disability, blindness and death.
what is considered premature?
birth before 37 weeks
what is extreme prematureity?
under 28 weeks
what is very premature?
28-32 weeks
what is moderate to late preterm
32-37 weeks
when is resuscitation carefully considered in premature babies?
under 500g or less than 24 weeks
what does a CXR for respiratory distress syndrome show?
ground glass appearance
what are some features of fetal alcohol syndrome?
- Microcephaly (small head)
- Thin upper lip
- Smooth flat philtrum (the groove between the nose and upper lip)
- Short palpebral fissure (short horizontal distance from one side of the eye and the other)
- Learning disability
- Behavioural difficulties
- Hearing and vision problems
- Cerebral palsy
describe the usual excretion of bilirubin
Red blood cells contain unconjugated bilirubin. When red blood cells break down, they release unconjugated bilirubin into the blood. Unconjugated bilirubin is conjugated in the liver. Conjugated bilirubin is excreted in two ways: via the biliary system into the gastrointestinal tract and via the urine.
what is haemolytic disease of the newborn?
it is a cause of haemolysis and jaundice in the neonate caused by incompatibility between the rhesus antigens on the surface of the red blood cells of the mother and fetus.
most important antigen in the rhesus blood group system is rhesus D antigen
when a woman is rhesus D negative, she may have a rhesus positive child and at some point during the pregnancy her blood may mix with her childs at which point the babys rbc will display rhesus d antigen. mothers body will then produce antibodies to rhesus D antigen and the mother will become sensitised to rhesus D antigens
Doesn’t usually cause problems in 1st pregnancy but if second child is rhesus positive - mothers antibodies can cross placenta and attatch to fetus RBC. immune system of fetus then attacks their own RBC = haemolysis = anaemia and high bilirubin levels
what is phototherapy?
converts unconjugated bilirubin into isomers that can be excreted in bile and urine without requiring conjugation in the liver
baby placed under blue light in nappy with eye patches
monitor bilirubin throughout
once phototherapy is complete a rebound bilirubin should be measured 12-18 hours after stopping to ensure the levels do not rise again
